Imo no the h202 is not going to do anything. The plants will finish up but the more leaves that die and flair up the more mold that starts to fly around.
I’ve been at war for a long time with disease viruses. The key is to grow the healthiest plants and clones possible. Physan20 will kill it in your medium but most the time if it’s in the roots it’s also up in the stem already. So you need to clone out of it using systemic fungicides if you want to save a strain.
Anyways for bloom I reccomend actinovate and regalia once a week plus good husbandry tech. Make sure your sterilizing resivours etc weekly.
His plants will push through for sure, but once the inner cola leaves yellow die the mold sets in.